Tobacco smoke filter



Dec. l0, 1957 n.1'. sci-maus E1s-AL ,M5360 TOBACCO SMOKE FILTER Filed Oct. 4, 1955 INV ENT 0R35 5c-@@5015 ATTORNEYS TOBACCO SMOKE FILTER Hans TheoSchreus, Dusseldorf, and Fritz Schnhfer, Wuppertal-Vohwinkel, `Germany Application October 4, 1955, Serial No. 538,479

Claims priority, application Germany December 24, `1951 13 Claims. (04131-208) The present invention relates to an improved filter for tobacco smoke, for removing or rendering ineffective health-aiiecting volatile substances contained in the tobacco smoke. The new tilters comprise van extended, hollow chamber or cartridge, open at -both ends through which the tobacco smoke to be purified is passed and which contains means or materials for chemically binding or adsorbing health affecting volatile constituents of Athe tobacco smoke without destroying or removing the aroma of the tobacco smoke. The object of this invention is to provide a ilter of this 'kind of .increased efficiency. This patent application is a .continuation-inpart application of our United States ypatent application Serial No. 327,510, led December 23, 195,2, now

4to require large filter surfaces `if a Agood adsorption is to be obtained.

-It is also rknown to use cation and anion exchange materials, `individually as well as Amixed together, :as r.lil-

ter materials. It is true that basic and acid components of the tobacco smoke are bound in such filters. ,'However, it has been found that `the `harmful substances contained in the tobacco smoke which are neither acid `:nor alkaline, such `as e. g. aldehydes, or ketones, `will nevertheless pass this type of filten Furthermore, lknown filters have `the great disadvantage to .unfavourably in- ;fluence the taste of the 'tobacco smoke, -so that the smoker, having used y.it only for a short time, takes a dislike against such filters.

It has now been found that it is `possible to very etectively bind health affecting components of the tobacco smoke without `disadvantageously aiieeting its `taste `by using a filter which, besides `the known ion exchange materials, namely cation lor anion materials or Shot-h together, contains additional materials rwhic'h chemically react with the harmful, nonalkaline .and nonacid .components of .the smoke `to .form non-volatile compounds,

thus retaining the latter inthe lilter.

.As tothe cation Yexchange materials, all 'substances .known for lthis `purpose maybe used in the present .in-

vention, 'preferably-e; g. phenolsulfonic acid resins, sulfonic acid resins on-the basis of polystyrene, sulfonated lphenol resins, sulfonated polystyrene resins of the lower cross-linkage type, high-capacity rsulfonated .polystyrene resins, such yas for instance Amberlite IR-120, Amberlite XE66-B, Amberlite IR1 (R. Kunin, Anal. Chem. 21 V89 [1949]), resins of polyacrylic acid, `such as for instance Amberlite IRC-50, Amberlite XE-64 (R. Kunin vand R. E. Barry, Ind. Eng. Chem. 41 1269 [19491; I. C. Winters and R. Kunin Ibid. 460; F. X. McGarveypounds. v.carbonyl reagents, such `as e. lg. .phenylhydrazina .semicarbazide or thiosemicarbazide Land their substitution :and `then removing the solvent.

porous material.

2,815,760 Patented Dec. 1,0, 1957 icc lI? and Thomson, Ibid. 43 741 [1951], sul-fonated carbons and other substances. All of these materials are commercially known products.

Sulfonated carbon has proved to be particularly use- Vful. Preferably, a sulfonated carbon is used which shows 'such a mechanical stability that when being .stored or moved in the filter it will not disintegrate and will not cause any clogging of the apertures of the `iilter charn- Aber nor ofthe lter cartridge. This sulfonated carbon should possess such a stability that a carbon particle of about 1.5 mm. in diameter will not be crushed when charged with ,a weight of 200 g. Furthermore, this .sulfonated carbon should possess an adequate capacity of adsorption. This property may be tested by shaking for 10 minutes 1.1 g. of the sulfonated carbon in a solution consisting of 1'0 cc. distilled water, 1 cc. of a solution of 0.2% methyl red and l drop of 20% hydrochloric acid. `An adequate adsorption power of wthe icarbon is indicated by :the disappearance of the red color within this period. This sulfonated carbon is known and may be obtained according to known methods. `It is a commercially available cation exchange material.

As .to the anion exchange materials, for instance the following substances may be used inl-the present vinvention: Quaternary ammonium bases on the basis of polystyrene, phenol-formaldehyde-amino resins, secondary amines derived `from polystyrene, such as for instance Amberlite IRA-400, `Amberlite IRA-.401, Amherlite JIRA-410, .Amberlite IRA-.411 (R. Kunin and F. X. .M CGarvey, Ind. Eng. Chem. 41 12565 [19491; .1. C. Win- ,ters and R. Kunin, Ibid. 460 `[1949] and .other substances. All of these substances likewise .are known .commercial products. v

The nonacid and nonalkaline components of the tobacco smoke which exert a harmful keffect .are mainly carbonyl compounds, i. e. aldehydes and lketones, such as e. g. formaldehyde, acrolein, acetone, methylethylketone or a similar substance. They `may be retained in the iilter material by a chemical reaction with particular iilter substances with formation of nonvolatile .com-

For this purpose the known diliicultl-y volatile rby dissolving the desired carbonyl reagent in a solvent and/ or Vdiluent, such as e. g. water, methyl taleohol, ethyl alcohol, acetone, ether methylenechloride, dioxane, tetrahydrofuran or similar substances and by mixing the solution with the porous material, allowing to adsorb Activated carbon, cellulose, asbestos wool, chips of plastic material, nnburned ,earthen pellets, particles of `puxnice stone, paper meal, silica gel, cork, or a similar substance ,may be '.used as This porous material .can -be ,used in afgreat variety of shapes, such as, for example, particles,

pellets, laminas, punched or pressed Stoppers, powder or crystals.

The carbonyl compounds of the tobacco smoke may also be bound by means of difcultly volatile 1.2-arninoalcohols, the amino group of which contains at least one `unsubstituted hydrogen atom while forming oxazolidines for instance according to the following reaction.

H2O-,NH

HO.CH2CHZ.NH2 CH3-CHO= similar sub-stance.

The following 1,2-aminoalcohols may be used in the present invention: l-aminoethanol-2, 1-methylaminoethano1-2, l-ethylaminoethanol-Z, l-isopropylaminoethanol-2, dvi-22hydroxyethylamine, 1-hydroxy-Z-aminopropane, 1- aminocyclopentanol-Z, 1aminocyclohexanol2, l-methylaminocyclohexanoLZ, l-allylaminocyclohexanol-Z, l-phenyl-1-hydroxy-Z-methylaminoethane, 8hydroxy1,2,3,4 tetrahydroquinoline, 2-hydroxypiperidine, 1hydroxy1,2, 3,4-tetrahydroisoquinoline, 2hydroxypyrrolidine, glucamine, N-rnethylglucamine, N-ethylglucarnine or a similar substance. These 1,2-aminoalcohols, too, are suitably used as filter material, after they have been adsorbed on a porous material, such as e. g. activated carbon.

Furthermore, difficultly volatile 1,2- and 1,3-diarnines each amino group of which contains at least one unsubstituted hydrogen atom may also be used in order to bind the nonacid and nonalkaline components of the tobacco smoke, such as e. g. the carbonyl compounds, for instance the following reactions taking place:

Nia

aikyl For instance the following diamines may be used in the present invention: 1,2-ethylene diamine, methyl-2- amlnoethylamine, ethyl-Z-aminoethylamine, sym. dimethyl-1,2ethylenediamine, 1,3-propylenediarnine, l-ethylamino-3-propylamine, sym.dimethyl1,3-propylenediamine, 1,2-diaminocyclopentane, 1,2-diaminocyclohexane, or a These diamines likewise are suitably adsorbed on porous materials, such as e. g. activated carbon, as described above and used in this form.

Any suitable amount of the carbonyl reagents may be adsorbed on the porous substance. Especially good results were obtained with porous substances containing from 0.1 to by weight adsorbed upon them.

bases may be additionally used which may be adsorbed on the porous material, if desired, together with the mentioned basic carbonyl reagents.

The following organic bases may be used for this purpose: triethanolamine, 2-diethylaminoethanol, 2-dibenzylaminoethanol, 1-diethylaminopropanol-3, N-dimethylglucamine, N-diethylglucamine, piperidine, N-methylpiperidine, N-benzylpiperidine or a similar substance. However, no easily volatile amines or bases should be used because they would leave the filter during the smoking process, thus unfavorably affecting the aroma.

As mentioned above the compounds used according to this invention for binding the harmful components of the tobacco smoke must be difiicultly volatile, i. e. they must not be volatile or essentially volatile below a temperature of 100 C.

Suitably the filter for the tobacco smoke consists of an extended chamber which is perforated at both ends through which the smoke of burning tobacco may be drawn, and which contains the ion exchange material and the adsorbents of the described type. This filter material can be disposed directly within a cigarette, a cigarillo, cigar or pipe without any special casing. Alternatively, it may be contained in a special casing or cartridge which is disposed anywhere at a suitable place in a hollow chamber of the cigar or cigarette holder or in the pipe, so that this casing or cartridge may be exchanged against a new one as soon as the filter material has been exhausted. These casings may be used in a great variety of shapes, such as e. g. in the form of a cylinder, ball or cone. The hollow cylinder has proved to be a specially useful form.

The drawing represents a useful form of the filter casing or cartridge. The forms of the filters shown in the drawing are illustrated on an enlarged scale.

Fig. 1 represents a filter cartridge disposed in a cigarette holder.

Fig. 2 represents a central longitudinal section through the filter cartridge.

Fig. 3 represents a cross section through the removable cap of the cartridge along the line 3 3 of Fig. 2.

Fig. 4 is a cross section through the other end of the cartridge along the line 4 4 of Fig. 2.

Figs. 5 and 6 are perspective views which show particular embodiments of the sealing cap of the cartridge.

Fig. 7 represents a central longitudinal section through a preferred filter cartridge according to the invention in which the ion exchange filtering material and the ltering material which reacts with the organic carbonyl compounds, respectively, are not intermixed.

The filter cartridge may consist of materials, such as, for example, cardboard, glass, wood, metal, earth and plastic materials. Of the latter group the customary commercial products may be used, e. g. acrylic acid ester resins, acrylicnitrile resins, polyvinyl chloride, urea formaldehyde resins, phenolformaldehyde resins, polyethylene products, polystyrenes or a similar substance. A filter cartridge of plastic material is well suited for the claimed purpose; it may be colorless or colored, transparent or opaque. If the filter material is colorless, it is preferable to use a colorless transparent cartridge so that the coloring of the filter material by the tobacco smoke, and thus the degree of exhaustion of the filter material effected by the tobacco smoke, will be readily recognizable. However, when using a colored filter material, such as e. g. sulfonated carbon or activated carbon charged with the described substances it is advantageous to keep the wall of the cartridge, e. g. of the hollow cylinder, opaque while one or both closure members of the cylinder, e. g. the perforated sealing cap is to consist of a transparent material. Thus, the degree of exhaustion of the filter is easily recognizable from the coloration of the material as observed through said holes contained on those parts of the cartridge where the smoke enters or leaves it.

Fig. 1 represents a cigarette holder consisting of two parts 1 and 2 which may be screwed in one another. When being screwed together members 1 and 2 form a hollow chamber which provides for receiving the filter cartridge 3, shown in detail in Figs. 2 to 6. In the present case the cartridge is a cylindrical hollow body containing a mixture of granules 9 of filtering material according to the invention which at the end adjacent to the cigarette is closed by a jammable sealing cap 4 and which on the opposite side ends in a perforated terminal disc 5. The sealing cap 4 contains a number of axial or approximately axial bore holes 6, e. g. six symmetrical bore holes which are arranged in a concentrical circle and the axes of which may be differently directed, as shown e. g. in Figs. 2, 5 and 6. The terminal disc 5 which is integrally connected with or sealed to the filter cartridge suitably shows a concentric aperture 7 with support stays 8, as shown in Fig. 4. The bore holes contained in the sealing cap whendisposed with inclined axes as in Figs. 5 and 6 have the advantage toA bring about a turbulent movement ofthe tobacco smoke'during smoking, whereby thel lte'r materials contained in the:` `cartridge "are. better The dimensions of thecartridge may 'be adapted toany `desired purpose. of use. The following; dimensions are` :preferred which, when compared with .the jmeasures of known cartridges, additionally allow a more fashionable form of the holders and the pipes: The external length of the cartridge, without the sealing-cap., measuresabout 46 m-m. its external diameter being about 7 mm. The sealing cap 4 measures about 7v times 3 mm. and the sealed cartridgehas a total length of dabout 47 mm. Of course, these are only Voptimum dimensions for the cartridge, which, if desired, may be varied.,

Suitably, the yfilter cartridge is Vdisposed in the holder `or pipe `in such a manner that thesealing cap 4 of the cartridge lies on that side from which the tobacco smoke arrives and that thecartridge projects from the mouth piece 1 after `ituhas been screwedioif, so that therdegree of exhaustion ofthe filter effected by the tobacco vsmoke may lbe quickly recognized from the coloration of ythe sealing cap. When beingdisposed accordingly, thefilter when being examined needs notlto be lifted'from its place which always involves soiling the hands or anyinstruments used therefor. The cartridge is to iit tightly into the hollow chamber.

The filter material may be disposed `either in layers of .its particular components'which, -if desired, may Vbesepa- `rated by easily permeable intermediate walls, or, alternatively, in a single composition of the particular components which form the filter material. The lattermethod has proved to be `technically useful.

The grain size of the `filter material may vary in a wide range; best results have been obtained by yusing a grain having a diameter of about 0.9 to 1.8 mm. Thus,

beside a reasonable good filtering eifectan unobstructed passage or flow ofthe smoke stream during the smoking .process is obtained, which is still unrestrained even with strongly used and nearly exhausted lter cartridges.

The lilter material may also be incorporated `into the mouth piece of the cigarettes, cigarillosand cigars. However, this requires the use of a material having `a grain size which is `essentially smaller than -that used in the mentioned cases. Here the grain size is preferably about 0.2 to 0.5 mm. in diameter.

The question as to whether smoking through the filter of this invention would result in any deterioration of the aroma has been carefully investigated, and it has been found useful or necessary respectively, to use .special proportional amounts of the iilterrsubstances for binding the acid, basic and neutral components of the tobacco smoke, in order -to provide a iilter which vdoes not deteriorate the aroma `o'f the tobacco smoke and which nevertheless, effects a vigorous binding of the harmful components. `It has been Vfound that .the filters Yof this invention even bring about an improvement of 'the .tobacco smoke during smoking; for the-scratching and acrid 'pungent taste caused in the Vmouth bysmoking tobaccos Tof minor qualitymaybe preventedanda smoke'which by weight ofanion exchange material, `and lpart of vadsorbent with a 1,2-aminoalcohol; or 4 parts by weight of cation exchange material, lpart by weight of anion .exchangeimateriah 1 .part by weight-of adsorbentrwith a tg--aminealcohol and 1 part ofadvsorbeut with` hydroxylthe Water '-bath. 'This vdrying may sorbed thereon.

aminoacetate., A mixture consisting lof 2 partsof 'sulfonated:carbonwhich is sold under different trade'names and which, in smaller grain sizes, iszchiey used for `the purificationof water, and ofl part of activated carbon impregnated, with l-aminoethanol-Z yhas proved to-be specially successful.

EXAMPLE 1 Impregnation of porous material with organic [bases First, activated carbon (commercial) is tested by the following method las to its power of adsorption:

1 g. of -activateddcarbon is shaken in a-test tube with a red colored solution of'lO cc. water,.1fcc. of a 0.2% methy1l red'solution 'and 2v drops :of v20% hydrochloric-acid. Gradually, the -color is todisappear and after l0 minutes tlie'lliquor, uponV having been filtered, has to be totally color-less.

g. of an activated-carbon fulfilling these conditions vare intensely agitated Aor shaken with a' solution, rconsist- V"ing of 200 cc. water and 2.5 cc. l-aminoethanollZ for `(about -a Iquarter of anhour. Thereupon the solids Yare sucked offA Vand slowly 4washed with about 1800 cc. of Acold water. 'Ihe last amount `of-water Vis -to lindicate only a Weak alkalinereaction yon lindicator' paper, correspond ing to apH fofabout 7.2 yto 7.4. The activated carbon treated in this lmanner is driedinanevaporating dish y011 be conducted more carefully in the vacuum.

VlZhen` shaken with little cold Water this `reaction product should not indicate any alkaline reaction `with in- 'dicator paper. However, -when heating the aqueousmix- Ature 'in' a test tube `until boiling a weak alkaline reaction 'will occur.

Alternatively, alcohol, acetone, ether, dioxane, vor acetonitrile may vbeused as diluent .instead ofwater. The ractivated vcarbon with the material adsorbed thereon may also be lprepared as describedin Example 2.

In the same manner the activated carbon may be treated with the other mentioned .organic bases, such as e. g. phenylhydrazine, '1.2eethylenediamine, 1.3-propylenediamine, 2-diethylaminoethanol, vglucamine or va' similar substance.

Alternatively, the porous materials Imentioned above, such Vasl e. g. cellulose, asbestos wool, plastic materials, silica gel -or a similar substance, may *be used -in vthe above example, instead `of i activated carbon.

In this case the following method may be used. .The amine. is'first dissolved in a `low boiling solvent orfdiluent. Thereupon the porous material is added to the solution and the Lsolvent or diluent is distilledo lby heating the kmixture on a Water bath `and applying a vacuum, if `desired. Thus a uniform adsorption ofthe amine on cellulose, asbestos wool or any other porous material is effected. For instance, 1 g. of l-ethylaminoethanol-'Z is dissolved in 300 cc. ether and the solutionfobtained is addedto 10 g. asbestos wool while wellshaking. Thereupon 'the solvent is distilled olf by heating the-mixture' on a Water bath, thus leaving an asbestoswool lwhich contains about 10% of 1ethylaminoethanol2 uniformly yad- The material .thus obtained may be diluted, if desired, by mixing it in a ball -mill Withadditional untreated asbestos wool to form a material with lower eontentfof l-ethylaminoethanol-Z.

EXAMPLE 2 Preparation of the )lters In a glass tube 13 about 35 -mmulongand 5 fmm. in diameter provided with a perforated cap 14, as shown yin Fig. 7, first 0.5 g. of a cation exchange material -15 is introduced, e. g. the commercially available product on the basis of sulfonated polystyrene vresin (Amberlite IR-l20), having a grain size of about 1.2 mm. Therst layer is coveredwith'a small, wellpermeablecotton-wool topperl Thereupon, 0.1 g. of an anion exchangemat rial 17 is introduced in the tube, e. g. the commercially available product derived from phenol-formaldehydeamine resin having a grain size of 0.9 mm. After this layer has been covered again with a small, well permeable cotton wool stopper 18, 0.2 g. activated carbon 9, having a grain size of about 1.2 to 1.4 mm. and containing about of di-2,2-hydroxyethylamine adsorbed thereon, is introduced into the tube. The end of the tube is then sealed with a perforated cap 20.

In this case the activated carbon with the material adsorbed thereon is prepared as follows: l g. of di-2,2 hydroxyethylamine is slowly added to 1 g. activated carbon while well stirring whereby the composition becomes warm. The moist paste obtained is further slowly mixed with 19 g. activated carbon while well stirring. There is thus obtained a homogeneous powder which does no longer smell of the added amine, is dry and may be stored for any desired length of time.

It was unexpected that the filter materials may be mixed with each other, for, because of the different properties of the cation and the anion exchange materials as well as of the organic bases it had to be assumed that they would affect each other when in mutual contact for a long time. Since, however, such action did not occur it was possible to use a substantially simpler process for the preparation of the filter. By means of a filling machine, e. g. a rotary filling apparatus, it is possible to exactly measure the ready mixtures consisting of the different filter materials and to quickly and continually fili them into the cartridge casings. Even the placing of the sealing cap and the sealing of the cartridge with adhesive or by means of heat treatment may be conducted automatically.

The mixtures of the filter materials may consist for instance of I. 2 parts by weight of cation exchange materials (sulfonated carbon) and l part by weight of an adsorbent consisting of activated carbon with about 1% of 1-aminoethanol-2, or of II. 2 parts by weight of cation exchange material (sulfonated carbon) and 1.5 parts by weight of an adsorbent consisting of activated carbon with about 0.75 or 1% or intermediate percentage amounts of l-methylaminoethanol-2, or of III. 3 parts by weight of cation exchange material (phenol sulfonic acid resin), 1 part by weight of anion exchange material (secondary amine on the basis of polystyrene) and 1 part by weight of an adsorbent consisting of activated alumina with about 5% of phenylhydrazine, or of IV. 4 parts by weight of a cation exchange material (sulfonated carbon as used for the treatment of water), 1 part by weight of an anion exchange material (Amberlite IR-400, see U. S. Patent 2,591,573, a quaternary ammonium base with reduced basicity on the basis of polystyrene), 1 part by weight of au adsorbent consisting of silica gel with about 1% of semicarbazide and 1 part by weight of an adsorbent consisting of small paper balls with about 1% of glucamine, or, though less favorable, of

V. 2 parts by weight of an anion exchange material, e. g. Amberlite IR-413 (F. I. Myers, Eng. Ind. Chem.

35, 858 [1943]; R. Kunin and F. J. Myers, I. Amer. Chem.

Soc. 69, 2874 [1947]) and 1 part by weight of an adsorbent consisting of asbestos wool which contains about 1% by weight of 1-benzylamino-ethanol-2.

EXAMPLE 3 Test 0f the action of the new filters when compared with known filters The test can be carried out according to the method which has been described by the inventors in the periodical "Arzneimittel-Forschung, vol. 4 (1954), pages 75-79.

The smoke, e. g. of a burning cigarette is passed through a lter which contains the substance to be tested as to its detoxcating power, then the smoke is conducted through a tightly stuffed cotton wool column and finally through two washing bottles which are connected in series and which contain an n/ 1 or n/ l0 caustic soda solution and an n/ 1 or n/ 10 hydrochloric acid solution, the stream of smoke through the whole testing device being effected by means of the suction power of a water jet pump.

In order to obtain a good control of the smoke stream a round bottom flask with a stop cock is used which is connected between the water jet pump and the washing bottles. The speed of the stream is controlled so as to allow the burning of a cigarette to take place within about 6 to 8 minutes.

During the smoking process all tarry and less volatile substances, such as e. g. nicotine or other pyridine bases, aromatic compounds or a similar substance as far as they have passed the filter, are gathered in the cotton wool column, coloring the latter from a fair yellow to a deep dark brown. Those easily volatile components having acid properties are caught by the diluted caustic soda solution and those having basic properties are caught by the diluted hydrochloric acid. All components are determined by titration. The colored cotton wool column is extracted with ether in a Soxhlet apparatus. From the degree of coloration of the ether it is possible to determine even externally the more or less good effect of the filter. For a more exact test the ether solution is evaporated, strongly acidified with diluted sulfuric acid and titrated with an n/ l or n/ 10 solution of potassium permanganate at a temperature of 40 to 45 to reach the point, where after a reaction time of 1 minute the violet color of the permanganate solution remains stable. By this method of oxidation it is possible to clearly determine those organic materials which have passed the filter. For, the more cc. of the permanganate solution consumed (namely that nurnber of cc. of the permanganate solution which is necessary to obtain a permanent violet coloration) the more of the harmful substances have unchangedly passed the filter into the cotton wool column which is connected downstream. Or, in short: the greater the number of consumed cc., the worse the filter.

The following table contains the results obtained with no filter used, with known filters and with the filters according to the invention.

TABLE [Comparison of the filter of this invention with known filters. The tests were carried out with the smoke of one cigarette per filtern] The symbols contained in the second column have the following meaning:

l i l deep dark brown. l l -dark brown. l brown. -light brown. -=yellow brown. --=yellow. 0=coloriess.

'Ihe filter of the invention used in the above comparison contained the following components: 2 parts by weight of sulfonated carbon and 1 part by weight of activated carbon with 1% of 1-aminoethanol-2.

EXAMPLE 4 The good filtering effect was confirmed by an experimentwith a person being very. sensitive to nicotine when smoking. While this person was able to smoke without any inconvenience a cigarette in a holder containing a lter in the form of a cartridge about 3.5 cm. long and about 0.5 cm. in diameter, filled with 0.5 g. sulfonated carbon (grain size 1.2 to 1.5 mm.) and with 0.25 g. carborain (an activated carbon described in Die aktive Kohle by O. Kausch, published by Wilhelm Knapp, Halle, Germany, 1928 and 1932) impregnated with 0.025 g. 1-aminoethanol-2, the same person when smoking a cigarette without this filter had to stop after a few puis, because the known symptoms of supersensibility to nicotine became extremely apparent.

We claim:

1. A tobacco smoke lter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing granular ion exchange material, a granular porous substance and a difficultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product adsorbed on said granular porous substance.

2. A tobacco smoke lter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture comprising granular ion exchange material, a granular porous substance and a diicultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product adsorbed on said granular porous substance.

3. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing granular ion exchange material, a granular porous substance and a diftcultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product adsorbed on said granular porous substance in a quantity of about 0.1% to about 10% calculated on the Weight of the porous substance.

4. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture comprising a granular ion exchange material, a granular porous substance and a diiicultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product adsorbed on said granular porous substance in a quantity of about 0.1% to about 10% calculated on the weight of the porous substance.

5. A tobacco smoke ilter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture comprising a granular cation exchange material and a granular porous substance having absorbed thereon a difiicultly Volatile amino compound adapted to react with organic carbonyl compounds to form a nonvolatile product in a quantity of about 0.1% to about 10% calculated on the weight of the porous substance.

6. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture comprising a granular cation exchange material and a granular porous substance having absorbed thereon a diicultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product in a quantity of about 0.1% to about 10% calculated on the weight of the porous sub- 10 stance, and in which mixture the quantity of the granular cation exchange material is in excess over the quantity of the granular porous substance containing the adsorbed amino compound.

7. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture of two parts by weight of a granular sulfonated carbon with one part by weight of a granular activated carbon which has adsorbed about one percent of 1aminoethanol2.

8. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture of two parts by weight of a granular sulfonated carbon with 1.5 parts by weight of a granular activated carbon which has adsorbed about 0.75% to 1% of l-methylaminoethanol-2.

9. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture of three parts by Weight of a granular phenol sulfonic acid resin material with one part by Weight of a granular anion-exchange polystyrene compound and with one part by Weight of a granular activated alumina material which has adsorbed about 5% of phenylhydrazine.

10. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture of two parts by weight of a granular sulfonated carbon with one part by weight of a granular activated carbon which has adsorbed about one percent of 1-aminoethanol-2 and wherein the granular particles have a diameter of from 0.9 mm. to 1.8 mm.

11. A tobacco smoke filter comprising a chamber adapted to atord passage of tobacco smoke therethrough containing a mixture of two parts by weight of a granular sulfonated carbon with 1.5 parts by weight of a granular` activated carbon which has adsorbed about 0.75% to 1% of 1methylaminoethanol2 and wherein the granular particles have a diameter of from 0.9 mm. to 1.8 mm.

12. A tobacco smoke filter comprising a chamber adapted to afford passage of tobacco smoke therethrough containing a mixture of three parts by weight of a granular phenol sulfonic acid resin material with one part by weight of a granular anion-exchange polystyrene compound and with one part by Weight of a granular activated alumina material which has adsorbed about 5% of phenylhydrazine and wherein the granular particles have a diameter of from 0.9 mm. to 1.8 mm.

13. A tobacco smoke filter comprising a cylindrical cartridge perforated at both ends containing granular ion exchange material, a granular porous substance and a difcultly volatile amino compound adapted to react with organic carbonyl compounds to form a non-volatile product adsorbed on said granular porous substance.

References Cited in the le of this patent FOREIGN PATENTS 337,200 Great Britain Oct. 30, 1930 497,708 Great Britain Dec. 19, 1938 501,402 Belgium Mar. 15, 1951 

1. A TOBACCO SMOKE FILTER COMPRISING A CHAMBER ADAPTED TO AFFORD PASSAGE OF TOBACCO SMOKE THERETHROUGH CONTAINING GRANULAR ION EXCHANGE MATERIAL, A GRANULAR POROUS SUBSTANCE AND A DIFFICULTY VOLATILE AMINO COMPOUND ADAPTED TO REACT WITH ORGANIC CARBONYL COMPOUND TO FORM A NON-VOLATILE PRODUCT ADSORBED ON SAID GRANULAR POROUS SUBSTANCE. 